Can You Solve Exam Q Causing Twitter Storm?

A tough GCSE maths question which stumped thousands of students caused a social media outcry and ended up trending on Twitter.

Many students sitting Thursday's Edexcel exam were thrown by the second half of the GCSE maths paper, which many said was unexpectedly difficult.

Within hours the topic was trending on Twitter and a petition set up online calling on grade boundaries to be lowered when marking.

The question that most students were unhappy about was about a girl named Hannah taking a sweet from a bag at random.

This is the question:

There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow.

Hannah takes a sweet from the bag. She eats the sweet. Hannah then takes at random another sweet from the bag. She eats the sweet.

The probability that Hannah eats two orange sweets is 1/3. Show that n²-n-90=0

:: See Sky News' attempt to solve the equation below

Other students took to Twitter to mock questions in the paper where they were asked to calculate how much a child had raised for charity, one where they had to work out which garden centre sold the cheapest plants, and another where they had to calculate whether two bits of cheese were the same volume.

The Wikipedia page of Edexcel was also temporarily changed to read: "Edexcel, formerly known as w****** that f*** with your mind are an examination board for UK GCSEs."

One student wrote on a Change.org petition website said: "All past papers were similar in a way and they are the resources that were that were used by students all through the country to help them with this paper.

"A lot of people have done badly and would appreciate a retake of a new test or lower grade boundaries."

Edexcel's owner Pearson said students would be "treated fairly" by markers, adding that its exams aimed to "test the full range" of students' abilities.

Here is what we think is the correct solution to Hannah's sweets question:

1/3 = 6/n x 5/(n-1)

1/3 = 30 / n(n-1)

n(n - 1)/3 = 30

n(n -1) = 90

n² -n = 90

n² - n - 90 = 0